Temporal effects in commuter response to reward scheme

Several reward scheme-based projects implemented in the Netherlands have stimulated car users to avoid using certain links of the network during peak hours. This paper reports the findings of a model that was formulated to analyze temporal effects of the Dutch SpitsScoren reward scheme. On one hand, one might expect that reward schemes lose their effectiveness over time as individuals tend to return to their old habits. On the other hand, by changing their routines, individuals may enjoy their new travel experience, and that enjoyment may in turn lead to positive reinforcement and ultimately to new habitual behavior. On balance, the impact of these opposite processes may conclude differently for different segments of travelers. To disentangle these effects, a panel-effects mixed logit model that predicted the probability of applying different adaptation strategies, including the option of no change, was estimated. Because the various strategies may be correlated, the model also allowed for covariance between the options. Results indicated that socioeconomic and situational variables strongly affected travelers' adaptation strategies. Moreover, the effectiveness of the reward scheme changed over time and affected the various options differently. The estimated model also showed evidence of significant covariances between adaptation strategies.